On Fri, 25 Apr 2008 01:27:52 +0000 (UTC), Bertie the Bunyip
wrote in :

The best way to do it is with a steep bank. Very steep.


The bank angle may be quantified:


http://groups.google.com/group/rec.a...1d80a2e846a88b
John T. Lowry

Best turnaround bank angle phi (least altitude loss per angle
turned through) for a gliding airplane is given by:

cos(phi) = (sqrt(2)/2)*sqrt(1-k^2)

where k = CD0/CLmax + CLmax/(pi*e*A)
where CD0 is the parasite drag coefficient,
CLmax is the maximum lift coefficient for the airplane's flaps
configuration,
e is the airplane efficiency factor, and
A is the wing aspect ratio.

I know most ng readers hate those darned formulas, but that's the
way the world works. For GA propeller-driven airplanes, k is a
small number (0.116 for a Cessna 172, flaps up) and so the best
turnaround bank angle is very closely the 45 degrees cited by
Rogers and, much earlier, by Langewiesche (Stick and Rudder,
p. 358). For the above Cessna, for instance, it's 45.4 degrees.
For a flamed-out jet fighter, however, things are considerably
different. The formulas above, along with formulas for the banked
stall speed, for banked gliding flight path angle, and for the
minimum altitude loss in a 180-degree turn, can all be found in my
recent book Performance of Light Aircraft, pp. 294-296.
The following seven pages then treat the return-to-airport
maneuver, rom start of the takeoff roll to contact with the runway
or terrain, in excruciating detail. Including wind effects, the
typical four-second hesitation when the engine stops, etc.

John. -- John T. Lowry, PhD Flight Physics; Box 20919; Billings MT
59104 Voice: 406-248-2606